Effectiveness and economic evaluation of self-help educational materials for the prevention of smoking relapse: randomised controlled trial

Background: Most people who quit smoking successfully for a short period will return to smoking again in 12 months. A previous exploratory meta-analysis indicated that self-help booklets may be effective for smoking relapse prevention in unaided quitters. Objectives: This study aimed to evaluate the effectiveness of a set of self-help educational booklets to prevent smoking relapse in people who had stopped smoking with the aid of behavioural support. Design: This is an open, randomised controlled trial and qualitative process evaluation. Trial participants were randomly allocated to one of two groups, using a simple randomisation process without attempts to stratify by participant characteristics. The participant allocation was 'concealed' because the recruitment of quitters occurred before the random allocation. Setting: Short-term quitters were recruited from NHS Stop Smoking Clinics, and self-help educational materials were posted to study participants at home. Participants: A total of 1407 carbon monoxide (CO)-validated quitters at 4 weeks after quit date in NHS Stop Smoking Clinics. The trial excluded pregnant women and quitters who were not able to read the educational materials in English. Interventions: Participants in the experimental group (n = 703) received a set of eight revised Forever Free booklets, and participants in the control group (n = 704) received a single leaflet that is currently given to NHS patients. Main outcome measures: Follow-up telephone interviews were conducted 3 and 12 months after quit date. The primary outcome was prolonged, CO-verified abstinence from months 4 to 12 during which time no more than five cigarettes were smoked. The secondary outcomes included self-reported abstinence during the previous 7 days at 3 and 12 months, CO-verified abstinence at 12 months, costs (NHS and NHS and participant medication costs perspectives) and quality-adjusted life-years. Logistic regression analyses were conducted to investigate effect-modifying variables. A simultaneous qualitative process evaluation was conducted to help interpret the trial results. Results: Data from 1404 participants were used for the final analysis, after excluding three participants who died before the 12-month follow-up. The proportion with prolonged abstinence from months 4 to 12 after quit date was 36.9% in the intervention group and 38.6% in the control group. There was no statistically significant difference between the groups (odds ratio 0.93, 95% confidence interval 0.75 to 1.15; p = 0.509). There were no statistically significant differences between the groups in secondary smoking outcomes. People who reported knowing risky situations for relapse and using strategies to handle urges to smoke were less likely to relapse. However, there were no differences between the groups in the proportion of participants who reported that they knew any more about coping skills, and no differences in reported use of strategies to cope with urges to smoke between the trial groups. The qualitative study found that some quitters considered self-help booklets unhelpful for smoking relapse prevention, although positive feedback by participants was common. Conclusions: Among quitters who had stopped smoking with the aid of intensive behavioural support, there was no significant difference in the likelihood of smoking relapse between those who subsequently received a set of eight revised Forever Free booklets and those who received a single leaflet. Although many people had suboptimal strategies to prevent relapse and most relapsed, the Forever Free booklets proved an ineffective medium for teaching them the skills to prevent relapse. Further research should focus on interventions that may increase the use of coping skills when required.